[wp-hackers] Lock posts and multiple logins

[Dino Termini]

Hello everybody,

for a website I'm working on, I decided to use Wordpress as the main 
CMS. There are several people contributing to it, so I'd like to know if 
you plan to add the following features to Wordpress in the near future. 
I've tried to find a plugin that does what I need, but I had no luck 
till now.

1) Lock posts that are being edited: I know you can password protect a 
post you are working on, to avoid other people to edit the same content 
at the same time, but I am looking for something more "transparent" to 
the content editor, that automatically does some sort of check-in/check-out
2) Avoid multiple logins for the same user (from different computers, or 
just different browsers). I know I can use the function 
is_user_logged_in() and write my own plugin, along with something like 
update_option( 'user_last_seen', time() ), but maybe there something 
already made for this issue :)

Thank you for your help,
camu